Having lived in Leeds all my life it may be embarrassing to say (particularly on the SL site ) that until yesterday I had never seen where the river starts running under the station. Though this thread may probably not add anything new I thought I would still post a couple of photos I took yesterday (July 5 2012) and add some comments with my second post. This photo with this post shows the view where the River Aire starts running under the station, but some water runs off to the left.

This photo shows the water that has run (or probably just collects) to the left of where the river starts its run under the station in the first photo.

I wonder if anyone knows just how far the water goes that does not run immediately under the station and just how much water is in that area (which I assume is where the old Mill Goit or related feature once ran)?

When walking on the foot/road bridge across the river at the Dark Arches daylight can be seen upstream. That is presumably where the river starts its run under the station. I am though a bit confused (easily done I admit!) as the daylight seen from the Dark Arches does not seem as far away as I would have expected it to be. It is probably some sort of illusion in that the Dark Arches area may go much further than it seems and the start of the run under the river is nearer than I thought it would be. I hope this makes some sort of sense.

I think you should photograph it later today, when we've had the month of rain they've tipped to come down during the day

The usually gently flowing Nanny Beck that runs near where I live is running deep, fast and muddy looking just now (and smelling of sewers). Everywhere is utterly sodden with all the recent rain (and there's more to come!).

I wonder if anyone knows just how far the water goes that does not run immediately under the station and just how much water is in that area (which I assume is where the old Mill Goit or related feature once ran)?

Reference to the "black" (No 2/6) map in the Leeds set on the "Network Rail Archive" thread which Phill posted on that thread shows that as built there were originally ten arched water tunnels where the river goes under the station at the north end, which eventually emerge having been reduced to four at the south end.

Of the ten northern arches, the two outermost merge with their neighbours almost immediately. The eastern of these was contiguous to the entrance to the Kings Mill Goit. In around 1899 that Goit was blanked off by stonework completely sealing off its entrance arch, and Leodis photos of this work can be found both on Leodis itself and as pics added to various SL threads.

At some date of which I have no record (but would conjecture it may have been when the Wellington Station was completely rebuilt and the Art Deco Concourse constructed) the easternmost first, second, and possibly third of the northern arches were completely blanked off similarly to the Goit,in other words straight across the river channel with (roughly) north-south running walls. There thus remain either seven or eight arch entrances at the north end, but inaccessibility makes it difficult to be certain which is the correct number.

At least one of the blanked off arches is now a roadway connected to the Queens Hotel basement services area, but access to that is now protected by locked gates at the end of Sandford Street, and I am reasonably certain that the only remnants of the Goit to be found on railway property on the western side of Bishopgate Street/Neville Street are in the derelict cellars beneath the Art Deco Concourse.

On the reason for number the converging arches, I would guess that it might be connected with keeping them clear of detritus. There is, as has been noted on the various threads on the Kings Mill Goit(s) a respectable fall from the river at the north and its emergence to the south. Merging the arches would increase the flow considerably and help to keep the channels clear.

The remaining problem has always been when whole trees get washed down in periods of high flood and get trapped. The only remedy is to wait until the waters subside sufficiently to allow engineering teams in to cut up the log jams.

LeodianGood 'confession' flushed out interesting info by Jim.Likewise, for some reason I'd kinda thought the Dark Arches only 'happened' on the outflow side.

Also, I had accepted the fact that the river "stops and goes under the station". Of course the weir/dam ran off a head of power for something just like Otley's weir + Mill.

The inflow arches you photo'd are at the exact point of 'High Dam' which is still visible at lower tide. Water tumbles over this into and down through the dark arches.

The King's Mills are understood to have occupied the 19th Century site from 12th C >at the latest<. The construction of weirs and cutting water channels for the Mills was such a massive undertaking that they would be modified rather than completely moved.

And so although improved and built over, High Dam and water power were operational from perhaps before 1086

With the high rainfall in recent days I thought it might be interesting to see what the flow was where the River Aire starts to run under Leeds Station, so I went to have a look today (Nov 19 2015). There was however not as great a flow as I expected (that was likely to have been a day or two back after the extremely heavy rainfall in the catchment area). These are a couple of photos that I took. Something that makes me wonder about is that the support structure does not seem that strong, though as it will have been fine for very many years I guess it is still OK now.

PS. I took the photos just gone 12:00 when it was raining heavyish, as seen by the rain streaks in the photos!

PPS. Though the river was higher than normal it was still well below the bottom of the nearly finished Leeds Station Southern Entrance where the river comes out after passing through the Dark Arches.